National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 22May 2022
NIST Standard Reference Database 101
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III.G.7. (XIII.B.3.) (XIII.D.5.)

Compare vibrational frequencies for two calculations for NH3NH3 (Ammonia Dimer)

A = HF/6-31G*

B = MP2/6-31G*

scale factors=0.8985, 0.943
  symmetry   frequency (cm-1)   reduced mass (amu)   IR Intensity (km mol-1)
mode number A B   A B diff. ratio   A B diff. ratio   A B diff. ratio
1 Ag Ag   3434 3438 -4.1 0.999   1.092 1.090 0.001 1.001   0.00 0.00 0.00  
2 A Ag   3311 3293 18.5 1.006   1.027 1.027 -0.000 1.000   0.00 0.00 0.00  
3 Ag Ag   1667 1662 5.0 1.003   1.061 1.059 0.003 1.002   0.00 0.00 0.00  
4 A Ag   1121 1136 -15.7 0.986   1.165 1.157 0.008 1.007   0.00 0.00 0.00  
5 Ag Ag   398 466 -68.1 0.854   1.094 1.101 -0.007 0.994   0.00 0.00 0.00  
6 A Ag   114 145 -30.9 0.787   4.593 4.744 -0.151 0.968   0.00 0.00 0.00  
7 Au Au   3431 3447 -15.1 0.996   1.091 1.089 0.002 1.001   0.81 1.55 -0.73 0.525
8 A Au   1678 1677 1.3 1.001   1.068 1.068 0.000 1.000   42.21 38.45 3.76 1.098
9 Au Au   211 248 -36.7 0.852   1.035 1.036 -0.000 1.000   139.14 132.33 6.81 1.051
10 A Au   80 99 -18.8 0.810   1.014 1.015 -0.001 0.999   28.36 31.93 -3.57 0.888
11 Bg Bg   3431 3446 -15.1 0.996   1.091 1.089 0.001 1.001   0.00 0.00 0.00  
12 A Bg   1667 1663 3.8 1.002   1.064 1.062 0.002 1.002   0.00 0.00 0.00  
13 Bg Bg   98 133 -34.9 0.738   1.093 1.101 -0.007 0.994   0.00 0.00 0.00  
14 A Bu   3433 3438 -4.8 0.999   1.092 1.090 0.001 1.001   21.40 30.20 -8.80 0.709
15 Bu Bu   3313 3297 15.9 1.005   1.027 1.027 0.000 1.000   8.90 14.70 -5.81 0.605
16 A Bu   1651 1638 13.2 1.008   1.066 1.066 0.001 1.001   30.65 23.79 6.86 1.288
17 Bu Bu   1100 1109 -9.1 0.992   1.180 1.180 -0.000 1.000   458.37 405.67 52.70 1.130
18 A Bu   54 97 -42.5 0.562   1.042 1.044 -0.002 0.998   285.31 321.79 -36.48 0.887
scaled by     0.8985 0.943

See section III.C.1 List or set vibrational scaling factors to change the scale factors used here.
See section III.C.2 Calculate a vibrational scaling factor for a given set of molecules to determine the least squares best scaling factor.